Do not assume the `rad` remote being present, in case other use other naming
remote schemes. Instead, build the remote using the `rad .` and `rad self --nid`
commands.
The symlinking process of `build/upload` was not working, due to the command
consuming stdin, and ignoring the subsequent targets platforms. Use `-n` to
prevent this, allowing every target binary to be uploaded correctly.
The output is also improved for better feedback during the upload process.
Fintan Halpenny